Low
C (Flashing) on Halstead Ace HE

Your boiler has been manually or accidentally switched into a service testing mode, meaning it is running at a restricted low power level rather than responding to your heating demands.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

Technical description

The appliance enters the SERVICE mode (runs at minimum CH output).

DIY fix possible

Locate the selector switch on the front control panel.Ensure the switch is set to the 'Off/Reset' position for a few seconds.Turn the switch back to the 'Heating and Hot Water' position to exit the service mode.

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